Apparatus for commutating electric currents



March 23 1926. 1,577,685

c. s. BRADLEY APPARATUS FOR COMMUTATING ELECTRIC CURRENTS Filed July 6,1922 5 Sheets-Sheet 1.

WITNESSES INVENTOR March 23 1926. r 1,577,685

c. s. BRADLEY 1 APPARATUS FOR COMMUTATING ELECTRIC CURRENTS Filed July6, 1922 5 Sheets-Sheet 2 WIT/{E8858 INVENTOR March 23 1926; 1,577,685

c. $.BRADLEY APPARATUS FOR COMMUTATING ELECTRIC GURRENTS Filed July 6,1922 5 Sheets-Sheet 3 WITNESSES INVENTOR March 23 1926. 1,577,685

- c. s. ERADLEY APPARATUS FOR COMMUTATING ELECTRIC CURRENTS' Filed July6, 1922 5 Sheets-Sheet 4 WITH/E8858 "377 01? March 23 1926.-

C. S. BRADLEY APPARATUS FOR COMMUTATING EQECTRIC CURRENTS- ssheets-sheet s Filed'July 6, 1 922 I uwmron M440;- 4. $1M? er l-of "NewvfYorlg have' invented certain new 7 w and useful"IniproveinentsinApparatus for" the followingis eru11 andr1ea1i 'specificafl V inventionbeing more p jrticularly pointed 17 f of high voltage or vice; versa,fin which a ing flux in each. trans-former endin Which T30 a, separate.coll islprovided on each trans former essoclatedgby thesanie flux withthe L iirhich predeterminedtimes 50 :niul't neously withthe.priniaryrendsecond- Application fi led, Juiy 6,

T (ZZZ whomz't may:concern: v .Be1t known that I',CHARLES S; BB tnLm',

citizen of the Unlted States, residing at,

f Colninutetihg Electric Currents, of which ti'on,; illustrated in theannexed drawings,

1 out in thetinnexed "claims; f v I r i'lhis ep o'licationconstitutes acontinuation in part of niy application'serizil No. 241,161, filed Ju'ne21st, 191-8. a

--=Myinvent i0n relatesto an apparatus for connnutatingthe electriccurrent in coils, which are.assoeietedfby magnetizing flux, vandinWhi'ch thef energyof this flux' is 0011:, -serwied at, Tithe timecommutation" f occurs. Thisarr genient 01f coils 'soi e'ssoci'ated may'phe a liedaror iraiitiu 1o 'wpc'gses.,-

per '1 ieulanI2fi11'd it of ed'va-ntage' 'itransforming: direct;current] of -loizv Volta e into such plurality of trensfor ner"lenients" are provided Whose lnd vlduel primary and'secondaryjcoilsfareessociated bythe m g-mu primary I-and' "secondary, i this separate"coil v v'bein'g" short-circuited et the tilne' 'of coin'n u- I ftation0t the priinary and secondary" coil, so that the energy of themagnetizing flux is consented} by"thisycoil 'zind it also pre'i rents-the L; F. e f'thepi i nary an'd'sec Ondary: fron'i assum ngtheir'working value The particular forn efgepperetus which constitutes adirect" current t-rans'forxner v ,tatio'nery transformersfsiinilar tothos used-1n thes -a ltertion therewit-h' .a-rotm contictl device,

airyterminals.respectively of certein-ofthese nsforniers,iby"whichoperation these peri BRADLEY,

or ew YORK, -l\T., Y,

192'2. sefiarm. 573,115.

ticular transformerscease to remain active members of the series inwhich they were located T previous to the contact, their coils however,remaining in metallic contact with the circuit; at such times. v

In each of two parallel series' of such l transformers, a magnetic fluxisf produced'. & successively in each transformer in'oiie given 00] ydirection from a given maximum to elniaxi I the particulel novelfeatures "comprising-my mum=-in the opposite direction Eechfti'uns-f0rmere1ement is successively and eutonmtic'ally renderediineffectiveassuch by a r0 tar'y' contact device substantially as SVVOOII'HSCits'niaxirnumflux reached; The current 1 produced by the decline. of themagnetizing 'fluxf {is taken care 'ofhy it {special short Y circuitingWinding mounted on each trans- V. formerelenient ii -hi'ch windingis;Short-Cir,- cu'ited by ;a' spec tiell y zitthe time when the primalandsecondary coils of that. particulartmns- 5 x-fornier eleinent ereshortcircuited and cease f'ito b'eectiifer" By these means, sparking atthe Contact terminals of the primary and seco'ndary windings avoided;and the Contact shoe, [substan' energy of the magnetizing; current'iscon? sert'e'd by'jthe shorfi-circuiting coil which" niz y JoeWounddor'suchlow voltag'e that detrnnental spark ng lSIevoided zit itscon eis tactqterininals when the "said short-circ'uiting coil" is iopened.

Figures1,=2 a nd;3 show the transformer 1 I ser es -d1agrannnet cellyandconnected with the rotarycontact device hich-is shoivnin 1 invention isillustrated in the 'Eiccoim i jpanylngj drawn ggin which' transversesectionrespectively on the sec- .tiOndinesA-A, B-'B, C- C, in'Figure at;un'tilthe circuit is opened Wide enou l'tQ 40 prevent arcing; i

e storage hatteryis connectedecross the two Trot the character referredto hereiiibefore, ch a number, 1n tl1i is case24, are con nected inseries in such fashion, that their;

Figure 4 shows it longitiicli11al'-cent1al seetron through the rotarycontact de t'ice;

v enclosed inthedotted square f represents oue-- j.of the trzuisforinerelements I pi'iniariesjp, secondaries s, and "short-Cir curt coils mrespectively form a. closed cir cuit as' shoxqnin Figures 71, 2 and 3.To

simplify the illustrations, all'the transform,-

fer elements T are shown in the drawings arranged in a circle, but of'coursethey may be arranged in a y Way tofsuit the con yeniencej of thelocation, for instance like storegeb'atteriesi in: "tiers orv otherwise,sincetheir physical location 'doe'snot concern the I operat on involved111 the IPTQSEDEJBVBHUOIL..

Froni the junction points ot eclj a'cent coils of transformers T,congluctors; are led; to

contact terminals the"gmechanica-larrengedescribe. I

insulatingnneter1el,

ment" and operation of which illsh alli rnow J igure et the contact M"nden .0, 'pg ef h, has. d1

.Belferring now;

app atuss comp se posed} in its. center. In, shaft lit,

v both ends-at l2 and. 1.3 J. p r V i driven from: pulleyfli; fastenedto one. ot-

'its endsfl,;,Fixed to the shaft is an. insulnt w ing. leeye .15 en-tencling throughout its who.

=which: can, be

armsrlfl and ll of e ual lengthtinsuleted.

from e eel-1 otheryby l'eg spacing-ring 23 each arm ,clriiying; at itsouter); end; a; contact. sho e and} 21 liespectively; Both contact:shoes;

I rotateg ingthe; saine rediell plene. The side l tion. 05f. h e rm e si lus ted v gr.

u'reil-u ArnisQlGj and Q17 echj fere.connected; el' 'cellywithz-a, sling 24,125 res-pecnibera o-f E-Q ates With J shoes; 2t). and 21;" Foreach,- junee;

' tion point of edjacentprimerytranstorinen coils 79, one stud is provijded and; their outer ends are connected tofthesejunctionpoints;' I gassh own; in. Figure 1.:" l ?-heperipheral length of contactshqesi 20 and2111s made Whichr' they inclujd suflicient to just jbridge two tdjacentj con: tectstuds without short.-circuitingR-for an, unduly longertime the. "transformer, coil Assu mngnow. or a; joinent the; position.

"oil the contact i armsj; 1,6 and. 11, shown; in

Figure 11, We have: the; V following two; paths of the current: frombrush. 1' 9 (Dyer-slip ring -25youtunrdlyg-through arm 17, contactfsh'oe' junctionipoints-of theprimerygcoil of trans-E fo'rmjcn elementT1 thencetothe right and left successively through ;the primaries ,of

the other transtorrner elements; to the I j use, tion points of; the,primary-of:- transfor er. T studs-22 in contact with: shoe -20, in;-

st'uds;,; orderto-stfll "be able to accomif nodete' the same numberv ofstuds on the sex-oral radial planes and lnodifythe 111 This is.show-11in Figures 2 end-lto which d I now refer.

incent. secondary. i coils 5- Z and ;Whiich cnrr contact rollers.rsn'nilargto' those; stu 22,. described before, ere'--d1 sposedon. cyhne ranee ende'c in e radial planes 'as it clearly appears. from,

studs 3.61 :are; shown.alternately i n'.';se'ct-ioni Figure. 4), .andin'full View. By thisge edj ucenti stu'dsiis materially lessened. i

radial eontactl ehnement: with. each; other. 11 the directionofithecylindereexis so- ,thetfin"Figure 2 shoe vere ruseclifwithelldstuds' 36'- arrenged *lnone radial plane,v such as has been:she-W111;

V v 31 rotate,,eacl1'junction"pointbetweentwof."

21 the two,- studs 22'i in conta ct thereWi-tln:

iney be -plnced in thesani'el radi 211 planes: ivi'th ,ess

Wardly througharm 16, slip ring, 24; and brush 18. r

. For the secondary coils 's'thetransformer elements T a similar-contactarrangement is providedwiththeexception that, .on account" oti'the;hightension currentwhich these coils carry, litisnecessary to increase thedistance-J between two 1 peripherally adjacent Contact periphery"ofthecylinder as there are seconde'ry' coils, I distribute the studsoverrangement of theoontuct arms.accordingly.

'llhe contact studs 36 n Figure 2, Whicl areconnected to the junctionpoints of ed de-r 10, eqni-clistent from eachother in p ripherel: 5direct on. as. shown in y Elg-{LIIF6 2 but. they H are. arrangedalternately in to F igiure 4; so thatjni each radial plane theperipheral,distance between.;two; adja'c'e' studs '36 is twice the.distance between; two adjacent; stu'dsi22 in Figure T-h-is also. clearlyappears I from; Ffigurev 2'; Where the (correspondingfto the sectionllinej (IQ-C} in pedlient the; dangeroffiesh-pyer' between.

,On the-:insu tecl'she ftll ia-rje fiXedtwo P1118313 Bfiisfieby side int only; arm- 31 is visible; 1 Each erlngrotatesone:- of the-itwog redialplanes: in Which studs 21- 36w1're disposed, 'softh'et; the farmscooperate byrmeansi of their; contact shoes 39 3.951With T theirrespectiwe row ofstudsy Both arms m et- 1110. lee e- 41, which; carriesat one ofits, ends it slip ring 35 on Whiclrjbnush 9 slides. By; virtue:offithe fact that the two" Contact shoes 39,39? are in; exact;alineinent, the -eifect, soffzut 'aspcontect ti-nies 'ere concern'ed, isthe-seine as if only one: contest and descl'iloedv for instance withreference? to arm; 17, contact-i shoe 21; and studs" 22 -ini F igure?1-.. In other Words,- when 2111115131,

adjacent: secondary coils is successiarejlyacon nectedio brush-fia.1

.Dieinetrically opposite arms 3l':a.'nd1 31 l are placed similarly;nlined Contact; {grins 30 and! 30*; I "While contact: arms e01.-;a11 1 3arms 31 "and? 31*; this is gflnechuniciillyf not .oiidaries each otheratfl their hu carries-5. at {one of its ieirv wlneh brush 32 of-gthesearms, contactar'ms 88 38- are pro..-

s aslip ring 34, on

vid-ed and the-arms and-;.their shoes are in i 'qalinenient similar tothe arrangementot arm's-a3l, 8-lf*lso thatein Figure Qonly min: -(liandshoe 38-are:-visihle. I have-now pro vfided a second set ot'icon'tactstuds 36 altern ately disposed inpthe two {radial planes, in V.15-;Whichrarms,30,. 30 rotate and these studs c '3 correspondintheirperipheral positionsexfactlyivith studs 36 thestuds of the two; scs ;\'\-hich- ;z'u'e similarly locatedionthe .perip'hery inthe'direction o'f-theI-cylinder axis Edi-being connected inparallel byzasconductor V /l 2}as-shown;inFigure-AL;"Therefore inFigure 2" onlythepstuds of set 36 are vlsiblep Thusvt-he; entire effect of thearrangement I thatjarm's 30,30ioperate as if they were g5 connccteddiametricallyi opposite arms '31, Y 81? respectively inthe' -same,radial planes. f Thesexpairs of parallel connected studs of.v 5- the two:sets are successively connected to the junctioi'ipointsfof thesecondary transe aofljfor'mer coils $5,1 shQWnJin Figure4,:so that V a Icontactroller'r similar to those ofthe other inefife'ct anarrangeinentfis' obt-ainedis'imil'ar ih t wn n f alli'studs Werearranged in one rad al;

" plane as 7 described with} reference to F \l ithg-(Figure a) ,1 armslip ring- 34,-; hrush 32;theother branch'flowing over arm- 5 25.31fishoe 39? (Figure 4'); stud 36-in-'cont act therewith}successively-.through the sec- 36 shoe 38in contact "therewith (Figure 4),'-1&I'H1113O, ring 3% andbrush 32. f-AhiSlip ring {34"botli branclies jongain. Itsho-uld be noted that :contactlf'studs 36'; parallel-con";

nected With-studs .36 (Figure 4) cannot be I seen inFigure:2; sincebothsets appear -eX-- I he ith-erch other in that figure, H Ytracing;thesefitwo branchcircuits i "FIg-LlIES-Q: and :4 sho'uld'heused. j

ment forthmentioned n @n sin ft 1 jino tinted-1 two dialnetricah ositelydisposed arms-47 aha-4s, each slides? 1011 theyouter ends,-

.. cyli'n'derlO', in Whichitis held in positioniby b a;i1ei fa ams; 7from brushi8'3ii over slip ring 1; 35, dividing: itselt intovarr ns31',231 -one branch fiowing,

cot transforn1ers T L; tflastud ha-llt new: idesc ibe i the contactarrangehort-c-ircuiting coils -m afore' reference'now torFiguresf' Y 11agivenjdesignof transformer,elementsl.

' rfro n the'shaft and insulated from a manages: (Figure, 4); Their 1'in temy contact shoese and 5O re;

radialplane. iththese contact shoes 00- operate contact studs 52moun'ted on cylindrical-portion 10 in the-same; radial plane with shoesLS-and- 50. Cylinder 10 is fitted with itsflanged portion 51 in acorresponth ingly recessed flange portiona56 provided on studs so as toshort-circuit two adj a'centcoils.

for the purpose to be explained hereinafter. Th sperlpheral lengthhowever 1s chosen isufiiciently' great, soas to continue thisshort-circuit until the bridge formed by the primaryand secondarybrushes between two. of their respective adjacent studs has been openeda sulficient distance to form a safe gaplwhich cannot be broken byadisruptive j discharge-Which may occur at these studs.

'Eachstnd in F igureBv is providedwitha setsjotstuds described before;[The operation of-thef leviceviis as loWs,:j 1

Referring *tlo Figuresgl and Q, let us as;

'sume that lo-Wtension 'directcnrrent is sup:

,spectively, which both rotate ini' the same pliedto'priinarycoils p(Figurel) throughbrushes 18 and 19. This.{cu-rrent atraverses 0011s 1)mtWo parallel. series as descr bed 7 before-with referenceto Figure 11Let us further assume that forthe moment all the contact arms o'fthederice'stand in the position, shown in Figures 1, 2 and 3. Then are havein Figure, 1, one series. including the primaries of transformers T Ttheother series including the primaries of transformers 'T l. Theprimaries of trans- Each series of primaries represents a-substanti a1inductance, composed; of the inductances of the individual primariesp,-so that it takes 'an appreciable time forthe, flux to formers T and Tcarry at that moment'.

pass from a maximum in one directioirtoa inalximumjin' the otherdirection in each transformercore. Let us .saythis takes, torone" onehundred and twentieth ota second (assuming 60yrlevolutions per, second).Let us further assume thatfin- Figure: 1, arms 16 and 17nowstartrotating in the direction of arrows a"' and that contact-"shoe20 just;

' comes a maxii'nu'n'l; ,biit

. abl'efspeed and thu leaves stud 5 22. so that i he primary I p or;

transformer T is '1 just included; in thenpper series.v w transformerelement T the fluicwas I i'l'ia gima plus-r t o inaiii muinminus-"Whichspeed 05f the arms-{16 fend" 17 is such that at,

Ora-bout the expiratiorror this time, con-t tact shoe :21; has arrivedinthe place in which shoe is now showm i.- e1 oafter'one half "revolution,primary 7) of transformer This". againremoved" from the upper series,

its 'prilnary'p iscoinmutatedout of the maincircuit; and its flux is;conserved.

inthe-- l'o wer series f-( T flux Commences. to change 1 shoe 2 0arrives"in the position Whichflshoe 2 1 1s-now'shown, 'in-which pos V ofa transformer; ;s0 connected;1 egg in be The above-describe coil of anytransformerelement is connected in aiiyottlm t 'oQseries, We alwaysliave a removed;

the primary coils 17,-8; similar change in fi'ux and transfer from] one;series ;1nto,-th'eother takes "place with respect. to the secondary Mcoils sh Nowby-th'el changing flux inrth'ei trairstormer cores contained"in each: of 'the two series, acurrent in fa givenidirection finducedf'i nwall the secondary coils locat'edia-t" EVi'Ousthfat'by"introducing high tensiolrdi A Thus we" have current inducedinjth'e' thetime in fei therof the two series; v

secondaries of 'ieach series which in 'each 'seriesalwa ysflows in thesame 'direction -r [The two "secondary series; being connecte'dl.

in parallel by the contact arms ;"31, direct cur enem be skat satabrus'l'iesi SQ'and' H Itdsfiinpottzintto note that-during" the goccurrences described in the foregoing, the main. part of the en'ergy' lto commutating positions',i theifenergy of the magnetizing cu rrnt -iwhich terms;

b: a; maximunratthe moment-When its coil ,9 Was."short-circuited;and-the flux new de 'lclinesiga little it starts to change from we'fassume takeso'ne one hundred" and twentieth o f a second; It now therotation Icircuiting coils m with-ftheir contact mecha- FigureB;

Atthe? same time a slmil-ai' occurrence ;-talfies place Withiefer'enceto-th'e primary- 12 of tra ns" 'V about reached theirmax-iinuin flux, about=. ion the flux respective Sims.

.7 I cycle occurs s'uc'c e'si; sively' itlrrega'rdto eaclr transformmerit whenthe arms' rota te at' 'the'isuitso long 7 as a primaryipositions of the studs connectedi, to-""-thepri heseries until it is again V "marles and secondaries,Iuntd thebest posie When all 'happens withrespect to? brush es-F18.- and-'19, andlthuszthe device may anyegzcessamountOf energy, which; the

ike ,ilrany' ordij- 'n'ary; alternating current tran former, 'is V w v:the tertiary co1ls.- Asshownin F g, 5;l1WO':

y; 1:'whenihowever during thisf opera- I I V tion, the transformereleinents are placed 1n- 4'Z,48=, eaclr of Which rings is connected w thsmall by means? of conductors: 74, each part of tlicn1ai=n energysuppliedto t-hesystem, remains in-theinagnetic fiuxi Now; I nrorder thattlllS fluxa may not' pr0ducenism described before" with reference to" IThe arms 47' and3 l8 arefixed oir-t-he shaft, in: such angular relationto the'f other arms thatithei-rcontact shoes 49- aiid' 89 50 open -theshort-circuit o'i coi-ls' mofthe transformers, which are in commutatingi position at the time, or slightly prior-tothe time, when theprimaries and.secondaries; of these transformers pass from; comnmtat -fing position over v intoatheir other parallelseries; V y

Furthermore, shoes 49 and'50 are prererably of sufficient peripherallength so that; they close the short circu-i'ting coils m CF 0. thosetransformer elements; which] have the same time at which the:primariesand? secondaries: ofithese transformers are short- I 1 circuit'ed incominutatiiig posit-ioni "byftheir" 111 order to determined-h eunostffiavorable positions of opening and closing of short o ci-rcuitingcoils: 2n, I hwe mounted V the coin 'tact'studsf 52 ofjthese coils onthemovable 00 cylinder-'10s, southatg'the's'e studsxmaybe. slightlyzshiftecl angularly'relatively-to the lVhile I have described in;the-foregoing" a; sor-cal l'ed step-up transformenk git isflob-li rectci'irrent into coils 8,;low tension direct current may bederived. fromcor-ls. p at the r-J 1 be used'as a step-down; transformerwithoutchanging the struct m'e or the mode o fhop'er- Moreover, in order toconveniently" storef primer; on secondary; system'smight becalledj 7upon to *absorb I: provide a; storage battery 7 3 connected Wltll'ftllGcircuits yconta mngslip'ring'saof which only 7011s. shown in]? 5,7 areprovided-laterally adj ace'ntwto'arms one of theshoi-tT-fcircuiting1,brushesl4t9f50;

1,577,685 if. v V I7 1 gtutls nounted n sjai'clcylinderand-connecthaving a Contact shoe atits free-end, said jedto succe-ssi'vejllllCll'lOllPOlntSOfSillClCOilS, anus being electrically connected witheach 10 saicl studslbeing inguntecl on said cylinders other and theirshoes being in alinement in i alternately in several-radial'planes tointhe. direction of the cylinderzuxis t0=connect Q5 crease tlie pgripheal-ldistancQbetween two successive junction points'of-saicl coil seriesstudsconnectedt'ofsuce ssive' junction points, "co said arms whentllelilttrlOtfll'B. -a Qc'on tzibtflziym for the studs in each racliil Ki V j flung-rotatableinsaid cylincleiyeach arm I CHARLES S. BRADLEY.

